Abrasive belt retaining assembly



Jan- 21, 1964 1 c. BoGAERTs ABRAsIvE BELT RETAINING ASSEMBLY Filed Jan. 25, 1962 INVENTOR. le@ C jefzs' BY al@ l l ,46, 5A Mfg/S.-

nited States Patent O 3,118,259 ABRASIVE BELT RETAlNllNG ASSEMBLY Leo C. Bogaerts, Antioch, lll., assigner to Ammco rllools, lne., North Chicago, lll., a corporation of Illinois Filed lan. 25, 1%2, Ser. No. 168,638 2 Claims. (Cl. 5i-181) This invention relates to assemblies employing abrasive belts, and is directed more particularly to such assemblies in which the abrasive belt is wrapped around a rotatable cylinder or arbor for grinding and like purposes.

Heretofore diiiiculty has been encountered in securing abrasive belts to such arbors. Unless properly held to the arbor, the belt will not remain properly aligned in a grinding position on the arbor during operation of the assembly. Also, if worn by use, both the belt and the hooks thereon had to be scrapped.

With the present invention, the problems and difficulties of the prior art are substantially overcome by the provision of hooks having thermoplastic spikes or rivets thereon which pass through openings in the ends of the belt. The ends of the rivets protruding through the belt are heated and bent over to lock or heat weld the hooks in position securing the belt, the belt being mounted on the arbor with the ends thereof in a slot formed in the arbor, and the hooks then separately clamped by clamping members mounted to the arbor in the slot to secure the belt in position on the arbor. In this manner each end of the abrasive belt is provided with a flange member or hook secured thereto by plastic rivets and is separately clamped in spaced relation to the other hook by the clamping members in the slot formed in the arbor. The belt hooks thus facilitate assembly and disassembly of the belt to the arbor. Thus, with the present invention, the problems of securing the belt ends to the hooks, the hooks in the arbor slot and the belt to the arbor, are simplified. Moreover, when it becomes necessary to replace the abrasive belt, the cost occasioned by replacement of low cost and easily manufactured plastic hooks is generally a small percentage of the replacement cost of comparable metal hooks.

it is therefore an object of the present invention to provide an abrasive belt assembly which is capable of being easily and inexpensively manufactured.

Another object of the present invention is to provide new and improved clamping hooks for attachment to the ends of a split abrasive belt, said hooks having heat deformable belt attaching members constructed of a plastic material.

Still another object of the present invention is to provide a clamping assembly for locking an abrasive belt in position on a cylinder including hooks constructed of a plastic material and having heat deformable thermoplastic spikes thereon which pass through the ends of the belt and which are heat deformed and bent over against the belt to secure the hooks to the belt ends.

A further object of the present invention is to provide a split belt having an abrasive surface which is adapted to be wrapped around a cylinder and held in position on the cylinder by plastic hooks secured to the ends of the belt by plastic rivets, the ends of which pass through the belt and are heat deformed and bent over against the belt to secure the hooks to the belt.

Another object of the present invention is to provide a new and improved assembly for securing the ends of a belt, wrapped around a cylinder, in clamping means.

These and other objects, features and advantages of the present invention will become readily apparent from a careful consideration of the following detailed description, when considered in conjunction with the accompartying drawings wherein like reference numerals and ice characters refer to like and corresponding parts throughout the several views, and wherein:

FIG. l is a top view of an illustrative form of a brake lining groover, including an abrasive belt, constructed in accordance with the principles of the present invention.

FIG. 2 is a side view in partial section of the groover of FIG. l taken along line 2 2 of FIG. 1.

FG. 3 is a fragmentary View in elevation of the groover of FlG. 1 illustrating the grooving tool employed with the lining groover.

FiG. 4 is a view in elevation of a retainer or hook for attaching an end of an abrasive belt in the arbor slot `of 'che groover of FIG. l.

FIG. 5 is a view illustrating the hook of FIG. 4 attached to an end of an abrasive belt by heat deformed plastic spikes.

Although the present invention has a variety of applications, a suitable environment therefor appears in my copending application, Serial No. 121,810, led June 27, 1961, wherein is disclosed a brake lining groover, including a spindle upon which is mounted a cylindrical arbor for rotation with the spindle, and an abrasive split belt supported on the arbor which is adapted to rotate with the spindle and thereby grind the surface of a brake lining when brought into Contact therewith. Both the arbor and abrasive belt are provided with aligned slots through which a tool bit may extend, the tool bit being rigidly supported on the spindle. The arbor is one embodiment disclosed in my above mentioned copending application is slotted to receive the end portions of the spit abrasive belt. Clamping members, forming a belt retainer, are mounted in the slot to hold a pair of belt hooks, attached to opposite ends of the belt, in spaced relation on either side of the slot inward of the outer surface of the arbor. Each of the clamping members is provided with an aperture aligned with the slot of the Varbor so that the tool bit extends from the spindle through the clamping member apertures and arbor slot with the bit thereof in position for grooving a brake lining.

Referring to FIGS. l and 2 there is shown a brake ining groover 8 which comprises an arbor 9 mounted on a spindle il@ adapted to be rotated by a source of power (not shown). Rigidly supported on the spindle lll is a tool holder l2. The tool holder l2 is bored and slidably disposed on the spindle lll as clearly appears in PEG. 2.

The tool holder yl2 is provided with a bore 14 which extends perpendicularly to the axis of rotation of the spindle l@ and a locking dog 16 is slidably disposed within the bore lll. The dog lo is maintained in contact with a flattened portion i3 of the spindle i9 by a set screw Ztl. The hat portion l of the spindle lll, :the dog 16 and set screw 2b cooperate to positively lock the tool holder l2 to the spindle le thus fixing the relative angular position of the tool holder l2 with respect to the spindle lll.

rEhe tool holder l2 is provided with another bore 22 CFK?. 2) in which is disposed a tool bit shank 2d carrying a tool bit 25. A threaded set screw bore is drilled into the holder `l2 and intersects the bore 22 at a right angle thereto. A set screw 23 disposed in the set screw bore of the holder l2 is provided which holds the -tool bit shank 24 firmly in position in the bore 22, It will be appreciated that this arrangement of shank, holder bore 22 and set screw 2S permits limited axial movement of the tool bit 2d to and from a predetermined grooving position relative to the outer surface of the arbor 9. i

The arbor 9 is formed with an integral bottom support member 30 (FIG. 2) secured for rotation to the spindle 10 by a roll pin 32 extending through aligned bores 33 and 33a in the spindle 10 and the support member 3?.

The tool holder l2 is mounted on the spindle 10 in alignment with a longitudinal slot 36 formed in the arbor 3 9 so that the tool bit 26 is in position for movement inwardly of the outer surface of the arbor or outwardly of the `outer surface of the arbor to and from a brake lining grooving position as well as for vertical movement relative to the axis of rotation of the spindle lo for cutting liners in different locations.

The edges 33 and di? of the arbor 9 defining the slot 36 are rounded as appeared in FIG. l to m'mimize friction damage thereby to spaced end portions 42 and 4dof a split abrasive belt d6 which is wrapped around the periphery of the arbor 9 and secured by the ends 4Z land LEf-i thereof to a pair of clamping hooks 48 and which are retained in the slot 36 in spaced apart relation by la clamping assembly 52 which is mounted on spindle l in the slot 36 inward of the external surface of the arbor 9 and which is provided to flock the abrasive belt 4'6 firmly on the periphery of the arbor 9.

To mount the clamping assembly S2 in the slot 36, the spindle 1t? is provided with a pair of bores 55 and 53 (HG. 2) in which a pair of screws ed and 62 are threadably mounted, one screw 56 being located at the top of the arbor 9 and the other screw 5d being located near the bottom of the arbor 9. The screws dit and d?. pass through complementary holes in the clamping members 52a and 5212.

Each of the clamping members 52a and Sb is wingshaped in conguration. The exterior clamping member 52h is provided with two inwardly directed clamping elements and the interior clamping member 52a is provided with two U-shaped clamping elements 53 andrS positioned so as to receive the inwardly directed clamping elements of the exterior clamp member 52b.

' e screws 6ft and 62 are provided with retaining heads 64 and 66 which retain the clamping members 52a and 52th inward of the outer surface of arbor 9 in slot 36. A pair of springs 68 and 70 mounted on the screws and 62 respectively hold the clamping members 52a and SZb together against the screw heads 64 and 6d to urge the clamping assembly 52 to a predetermined clamping position relative to ti espindle lil.

Each of the clamping members 52a and 52b is provided with a rectangularly shaped aperture, 67 and 69 (PEG. 2) having vertical edges 7f3 and 'il and horizontal edges 72 and 73. The apertures defined by clamping members 52a and 52h are axially aligned with the slot 3e formed in the arbor 9. rl'he apertures so formed in the members 52a and 5211 permit the tool shank 24- and bit 26 to extend through slot 36 beyond ithe outer surface of the abnasive belt da for grooving of a brake liner. The apertures in the members 52a yand 52h are also of a width suiiicient to permit a wide vertical adjustment of the position of the tool holder 12 on the `spindle lll to permit positioning of the bit 26 for'grooving brake liners in different locations.

A feature of the present invention resides in the new and improved hook members or hooks 48 and Sti which fare provided to facilitate clamping of the abrasive belt 46 in the yarbor 9. Since these hooks 48 and Silv are identical in construction and oper-ation and may be used interchangeably for securing thereof to either end 42 or i4 of the belt 46, the description now to follow will relate to hook Si), it being understood that the description thereof is equally applicable to a description of the construction and operation of the hook d3.

As appears in FIG. 4, the hook Sil comprises a body portion Si? having a plurality lof spikes or rivets 82 outstanding thereon which extend preferably at an angle to the body portion `8l). The rivets or spikes 82 are constructed of a thermoplastic material, preferably a synthetic plastic, such as nylon, although it will be understood that any thermoplastic material having sufficient strength and rigidity may be employed in Ythe formation of the spikes or rivets S2. The spikes or rivets S2 are each frusta-conical in configuration with `the end portion thereof adjacent the body Sil, being of greatest diameter. The

21 spikes or rivets 82 are preferably staggered to provide an efficient holding arrangement when the outer ends S4 thereof Iare deformed by heat to secure the belt do to the hook 5@ as appears in FIG. 5. Preferably the entire hook is formed of the same material.

The belt te is provided at both ends 4-2 and ed with a plurality of openings 86 through which extend the spikes or rivets S2. The hook rivets 82 appearing in FlG. 4 have not as yet been bent over and deformed by heat to lock the belt to the hook body St?. For purposes of illustration, a pair of plastic rivets vS2 are shown in FIG. 5 with their ends S7 deformed by heat to emphasize the manner in which the rivets 82 are bent over against the belt a6 when heat deformed to lock the belt le to the hook body Si?.

After the ends 84 of the rivets 82 have been heat deformed and thus bent over against the belt i6 to form the rivet heads y87' (FIG. 5) and after the spikes or rivets 82 of the hook 4S have been so heat deformed to the other end da of the belt 15x-6, the belt 46 is now ready to be mounted to the arbor 9. the hooks Ltd and Se is provided with an `arcuate portion 9d terminating in a longitudinally extending end flange which is to be clamped between the clamping members '52o and 52!) as appears in FIG. 1.V The hooks 4S and 5t? may be constructed of any suitable material such as a plastic, and a preferred form df hoolebody is formed of nylon. `lf other suitable material is employed in the construction of the hooks 48 and 5t) the plastic spikes or rivets' 32 are lsuitably mounted on such material.`

`in mounting the belt de to the arbor 9), the clamping members screws dit and 62 are loosened to permit insertion of the flanges Z of each of the hooks d3 yand St? between the clamping members 52a and 52h. The sleeve belt 46 is slid longitudinally over the arbor 9 and the end flanges 92 of the belt hooks 4S and 5d inserted longitudinally between the clamp members 52a and 52h until the belt 46 is longitudinally positioned on the arbor 9 by indexing the edge 45a of the belt 46 against an `annular flange shoulder 36a `of the bottom support member 3i?.

The screws d@ d?, are then tightened to stretch the abrasive belt 46 over the arbor 9 and at the same time to increase the pressure between the clamping members 52a and 52h on the flanges 92 of the hooks Il@ and 5o by` compression of the springs 63 land 7?i In operation, a brake shoe (not shown) is positioned in a clamp (not shown), and the brake shoe ygroover of the present -invention'brought into engagement with the lining on the brake shoe and then rotated about the shoe while the spindle 10 is turning. TheV means for bringing the groover into engagement with the brake shoe, and for rotating it, may be any of a number of traversing devices well known in the art and such devices do not constitute a part of the present invention. The tool bit 26 will cut a groove in the brake shoe lining at the required position. The groove will be cut to a predetermined depth determined by the cutting edge of the tool bit 26, with respect to the surface of the abrasive belt 46.

After a groove has been cut in the brake lining to the predetermined depth, the abrasive belt 46 will then begin to grind the brake lining to form its surface to the correct degree of convexity so as to cooperate with its associated brake drum. This curvature results when the brake shoe is pivoted about a point distant from the lining to be ground by an amount which is equal to the radius of the brake drum, so that at the completion of the grinding operation, the surface of the brake lining on the brake shoe will exactly correspond to that of its associated brake drum.

During the'period Vin which the abrasive belt 45 isz shaping the lining the cutting edge of the tool bit 26' continues its grooving function, cutting always a groove' at exactly the same depth, as determined by the amount of penetration of the cutting edge of the bit 2e beyond the outer surface of the abrasive belt 46.'

The body portion of each of- When the lining has been properly shaped and grooved, the operation of the bralre lining groover is discontinued and the brake shoe is then ready for assembly in the brake mechanism of a motor vehicle. lt will be appreciated that as long as grinding continues by the action of the abrasive belt de on the lining, the groove in the lining will be cut, always to the predetermined desired depth until the grinding and grooving operation is completed.

When, for example, the abrasive belt 46 becomes worn and loses its abrasive effectiveness, the screws 6i) and 62 are loosened and the compression of the springs 68 and 79 is correspondingly reduced to thereby loosen the clamping members 52a and 521'; to facilitate removal of the flanges 92 of the hooks LS and 5i) longitudinally from between these clamping members 52a and 52b. A replacement abrasive belt de having hooks Lid and riveted thereto by heat deformed spikes 32 is then mounted on the arbor 9 in the manner heretofore described.

Although various minor modifications orr the present invention wl become readily apparent to those versed in the art, it should be understood that l wish to embody within the scope oi the patent warranted hereon all such embodiments as reasonably and properly come within the scope of my contribution to the art.

claim:

1. A brake lining grinder and groover comprising a spindle, a cylindrical arbor carried on said spindle and having a slot extending parallel to its axis, a sheet-like member wrapped around said arbor and having an external abrasive surface with edge portions of said sheetlike member extending through said slot and into said arbor, a pair of elongate hooks formed of thermoplastic, synthetic plastic material and extending along the edges respectively or" said sheet-like member, and each including an elongate body and a plurality of rivets arranged in spaced relation along said body and upstanding integrally therefrom, said rivets extending through said sheet-like member and thermoplastically deformed into clamping engagement therewith, retaining means carried by said spindle and disposed in said arbor for maintaining said sheet-like member in position on said arbor and having two pairs of opposed flanges, each pair receiving CII and retaining one of said hooks therebetween, said retaining means having an aperture aligned generally with said slot, a grooving tool bit having a cutting edge, and means supporting said tool bit on said spindle and projecting through said aperture and said slot with said cutting edge outwardly of the periphery of said abrasive surface.

2. A brake lining grinder and groover comprising a spindle, a cylindrical arbor carried on said spindle and having a slot extending parallel to its axis, a sheet-like member wrapped around said arbor and having an eX- ternal abrasive surface with edge portions of said sheetlike member extending through said slot and into said arbor, a pair of elongate hooks formed of thermoplastic synthetic plastic material and extending along the edges respectively of said sheet-like member and each including a body of elongate form having a ange and a plurality of spaced rivets upstanding integrally from said body on the opposite side from said ange and extending through Said sheet-like member and thermoplastically deformed into engagement with said sheet-like member and clamping said sheet-like member against said body and retaining means carried by said spindle and disposed in said arbor for maintaining said sheet-like member in position on said arbor and having two pairs of opposed anges, each pair receiving and retaining the anges of one of said hooks therebetween, said retaining means having an aperture aligned generally with said slot, a grooving tool bit having a cutting edge, and means supporting said tool bit on said spindle and projecting through said aperture and said slot with said cutting edge outwardly of the periphery of said abrasive surface.

References (lited in the tile of this patent UNlTED STATES PATENTS 1,162,098 Paszkiewicz Nov. 3G, 1915 1,582,390 Evans Apr. 27, 1926 1,759,523 Sims May 2G, 1930 2,046,122 Hunt lune 39, 1936 2,714,852 Stempel Aug. 9, 1955 FORElGN PATENTS 1,111,742 France Nov. 2, 1i955 

1. A BRAKE LINING GRINDER AND GROOVER COMPRISING A SPINDLE, A CYLINDRICAL ARBOR CARRIED ON SAID SPINDLE AND HAVING A SLOT EXTENDING PARALLEL TO ITS AXIS, A SHEET-LIKE MEMBER WRAPPED AROUND SAID ARBOR AND HAVING AN EXTERNAL ABRASIVE SURFACE WITH EDGE PORTIONS OF SAID SHEETLIKE MEMBER EXTENDING THROUGH SAID SLOT AND INTO SAID ARBOR, A PAIR OF ELONGATE HOOKS FORMED OF THERMOPLASTIC, SYNTHETIC PLASTIC MATERIAL AND EXTENDING ALONG THE EDGES RESPECTIVELY OF SAID SHEET-LIKE MEMBER, AND EACH INCLUDING AN ELONGATE BODY AND A PLURALITY OF RIVETS ARRANGED IN SPACED RELATION ALONG SAID BODY AND UPSTANDING INTEGRALLY THEREFROM, SAID RIVETS EXTENDING THROUGH SAID 